chimera Posted September 4, 2006 Report Share Posted September 4, 2006 Just curious... I think my coral growth has been inhibited by the 400W halides (or to be more specific, I think the height of the bulbs from the surface of the water maybe too close) The corals have adjusted to the higher light intensity (and I'm not getting any bleaching and am getting better colour), so the question is, if they are getting too much (or more than sufficient) lighting, could this inhibit growth? Some points: - Acro colour is good (actually, better with the 400's) - I still do get growth - just doesn't appear to be as much - Ca, Alk, Mg levels are all the same as they were prior to the 400W'ers - The lux meter indicates that the it's about 100,000 lumens at the waters surface, this is on par (no pun intended ) with sunlight in the tropics In summary, I'm running 3 x 400W'ers with the lumen arc design reflectors over a 5 foot tank and the bulbs are approx 9" from the water. Is this set too close? Or is it just coz I'm getting older? Is Darth Vader still alive? What happened to the ewoks? If anyone can shed any info, would be appreciated Quote Link to comment Share on other sites More sharing options...
wasp Posted September 4, 2006 Report Share Posted September 4, 2006 Interesting question, one I'd like to know also. Wonder if photoperiod would have an effect also? New thing I've just noticed in my tank, the tank is a 4 footer, couple of weeks or so ago I put a new 250 watt 14 k luminarc at one end, the other end has the old 300 watts 10 k while I'm waiting on bits to put a luminarc that end. Anyhow had a look thismorning and noticed that new sps growth has started pointing towards the 14 k luminarc, this is even from corals on the other side of the middle from the luminarc. The luminarc I'm waiting for will be 400 watts, so that will be an interesting test, against the 250 watter at the other end, see which they prefer. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 Anyhow had a look thismorning and noticed that new sps growth has started pointing towards the 14 k luminarc, this is even from corals on the other side of the middle from the luminarc. I staged my upgrade to the 400W with lumen arcs over a couple of months (or thereabouts) - a lack of money thing however noticed EXACTLY the same thing - all the corals started growing towards the right hand side 400W'er. A bit like outdoor plants really, they're all photosynthetic and grow towards the sun so it kinda makes sense. However the only question for me now is whether too much intensity actually inhibits growth! All other (water) parameters are stable and at optimal levels. The only other thing I did was stop dosing zeovit about 8 weeks ago but I'm sure the lack of growth started occurring before that. Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 4, 2006 Report Share Posted September 4, 2006 If I was you Chimera, I'd put 3 x 1000W over you 3 footer(sorry 5' ) and see what happens. That way we can you learn from your experience Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 well at least i'm prep'd with all the right gear when i upgrade to 6x3x2 next year its all experimental stage now, i believe less and less information i read on the net about reef tanks these days. everything is subjective and you can only learn from your own experiences (other than the obvious) Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 4, 2006 Report Share Posted September 4, 2006 ditto, except I'll be 2.3 x .65 x .9. Can't wait, and the only extra equip will be extra streams. Quote Link to comment Share on other sites More sharing options...
cookie extreme Posted September 4, 2006 Report Share Posted September 4, 2006 i have noticed the opposite when down grading. colour decreased but growth just went nuts. read in one of my books that corals can't do both (having awsome colour and grow fast) as energy is needed to either protect them from the extra UV in the form of pigmentation or it is used in growth. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 interesting, thanks chris. will see if i can dig up some more info Quote Link to comment Share on other sites More sharing options...
wasp Posted September 4, 2006 Report Share Posted September 4, 2006 Please share when you do! Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 4, 2006 Report Share Posted September 4, 2006 As far as photosynthesis goes, there is such a thing as too much light. I think it's called excitation quenching or something (from memory) where excess photons are converted to heat which changes the chemistry of those processes which make up photosynthesis. I don't know too much about it, but apparently it's possible. I don't know how that links with calcification, but remember that zooxanthellae and the corals themselves are competing for alkalinity. All in all, I don't think you'll find a lot of info on this. There isn't a lot of consistent info around on the links between zooxanthellae, photosynthesis, and calcification. For every study you find saying one thing, there's another which says the opposite. My gut feeling, and opinion, is that 400W halides are overkill. Also could what you're seeing be a result of changing bulb brands? Some bulbs, as bright as they may be, are crap for growth, others are excellent, all depends on PSD's Layton Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 Also could what you're seeing be a result of changing bulb brands? Some bulbs, as bright as they may be, are crap for growth, others are excellent, all depends on PSD's yeah, perhaps. i have 14k narva's on the right and left and a 20k XM in the centre. neither brand are doing well with growth (in other words corals in the centre are not growing faster than the left/right or visa versa) aesthetically the narva's are much more pleasing to the eye than the 20k XM IMO (even though i know that what we see is completely irrelevant to what the corals prefer!) Quote Link to comment Share on other sites More sharing options...
Feelers Posted September 4, 2006 Report Share Posted September 4, 2006 When you say that the lux measurement is the same as at the surface of the tropics - wouldnt that mean that things are likely very bright for the majority of corals which are typically found deeper than 70cms of water? For example what is the average depth of occurence of each particular species of Acro or Monti - sure some grow up to the surface but I'd guess that most corals are found below at least 1-2 meters to be totally happy, although I spose you cant really tell where they grow the fastest. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 When you say that the lux measurement is the same as at the surface of the tropics - wouldnt that mean that things are likely very bright for the majority of corals which are typically found deeper than 70cms of water? Indeed, but that doesn't mean that the intensity at the tropics is the most they can handle before growth is inhibited. Corals can adjust quite well to a number of conditions, the point of this question is at what threshold of light intensity does growth start to slow? (again, assuming all other factors are consistant) Quote Link to comment Share on other sites More sharing options...
wasp Posted September 4, 2006 Report Share Posted September 4, 2006 One thing to remember is even in a location where midday sun is directly overhead, before 9.00 am, and after 3.00 pm, the sun is striking the water at an angle less than 45 degrees. So presumeably some light is lost to reflection, the more full force of the sun would be felt for 6 hours a day. Quote Link to comment Share on other sites More sharing options...
wasp Posted September 4, 2006 Report Share Posted September 4, 2006 For every study you find saying one thing, there's another which says the opposite.Layton A phenomena that applies to more than just lighting. A study can be found to support nearly anything you want. Ask the tobacco industry! :lol: Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 4, 2006 Report Share Posted September 4, 2006 But wasp, usually there is an overwhelming consensus, with a couple of rouges who are just chasing funding money :-) Also, just because superficially they may appear to be opposite extremes, it doesn't necessarily make one right and the other wrong. It may just mean that we don't understand the details of what is going on well enough. Layton Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 4, 2006 Report Share Posted September 4, 2006 getting good growth and colour from the 14k Narva 400w, so don't know the answer Chimera, growth has increased since I changed, and colours still as good or better. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 4, 2006 Author Report Share Posted September 4, 2006 your tank is larger than mine, and I believe your lights are still sitting higher??? whats the distance from the bottom of your bulbs to the waters surface? can you measure for me pls? cheers! i think mine are 9" i'll check tonight. i adjusted to that height based on two things: 1. by basing the distance on the best spread of light from the analyzing reflectors web site and 2. by taking LUX meter readings to match approx what sunlight levels are in the tropics. the interesting thing is what wasp mentioned a few posts back, depending on where the sun is at various times of the day obviously changes intensity. lux meter readings at the tropics are around 100,000 during lunchtime. thats what mine is all the time. so, do corals prefer the weak to strong intensity that occurs in nature to happen in our tanks? i think i'll do an experiment (another one ) and raise the lights a couple of inches, test lux levels again then see what happens Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 I'll measure tonight and let you know. Quote Link to comment Share on other sites More sharing options...
puttputt Posted September 5, 2006 Report Share Posted September 5, 2006 I'll measure tonight and let you know. Quote Link to comment Share on other sites More sharing options...
Pies Posted September 5, 2006 Report Share Posted September 5, 2006 Having used 150watt, 250watt, 400watt halides, T8 & T5s my experance is a dramatic improvement in colour and growth when moving from 250s to 400s. My bulbs are approx 40cm from the water surface, I use 4. I currently only use the halides and have disconnected by T5s. I notice that where the light is most intense (the middle strip) is where colour and growth is the fastest. Colour is dull at the edges of my tank, which is where I grow LPS and softies. If I was to setup a new tank, it would use 400watt MH in lumenarc style reflectors. I can't imagine a better lighting setup. I remember seeing Zeovit NZs tank a few years ago, small cube about 2ft square. Without a doubt the most stunning coral colours i've even seen in a tank in real life. He had 4x 400watters over that tank. I'd be surprised of 3x 400watt halides over a 5 foot tank was providing anywhere near the same amount of light that the sun provides. You only have to look on RC totm to see tanks of similar size with twice the lighting, T5s squeezed into every free space to maximise the light provided to the tank. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 5, 2006 Author Report Share Posted September 5, 2006 I'd be surprised of 3x 400watt halides over a 5 foot tank was providing anywhere near the same amount of light that the sun provides. You only have to look on RC totm to see tanks of similar size with twice the lighting, T5s squeezed into every free space to maximise the light provided to the tank they're only 20cm from the water surface. the readings are also taken AT the water surface which matches the sun. it does not count light and spectrum penetrating into the tank which i'd imagine the sun does a considerably better job at! Quote Link to comment Share on other sites More sharing options...
Pies Posted September 5, 2006 Report Share Posted September 5, 2006 it does not count light and spectrum penetrating into the tank which i'd imagine the sun does a considerably better job at! Exactly. So the point of measuring it and saying its the same as natural light is...? If you think the problem is how close they are, could I suggest lifting them up higher? Quote Link to comment Share on other sites More sharing options...
Pies Posted September 5, 2006 Report Share Posted September 5, 2006 20cm? Your reflectors much be just about touching the water? Quote Link to comment Share on other sites More sharing options...
chimera Posted September 5, 2006 Author Report Share Posted September 5, 2006 If you think the problem is how close they are, could I suggest lifting them up higher? 20cm? Your reflectors much be just about touching the water? that's exactly what im asking, is the lower height (thus higher intensity) too much for corals to grow. if so, i'll raise them up. Quote Link to comment Share on other sites More sharing options...
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